Magnetorheological (MR) fluid is a type of a smart material that can control its mechanical properties under a magnetic field. Iron particles in MR fluid form chain structures in the direction of an applied magnetic...Magnetorheological (MR) fluid is a type of a smart material that can control its mechanical properties under a magnetic field. Iron particles in MR fluid form chain structures in the direction of an applied magnetic field, which is known as MR effect, resulting in variation of stiffness, shear modulus, damping and tribological characteristics of MR fluid. As MR effect depends on the density of particles in the fluid or the strength of a magnetic field, the experiments are conducted to evaluate the friction property under reciprocating motion by changing the types of MR fluid and the strength of a magnetic field. The material of aluminum, brass, and steel are chosen for specimen as they are the most common material in mechanical applications. The surfaces of specimen are also observed by optical microscope before and after experiments to compare the surfaces with test conditions. The comparing results show that the friction coefficient increases as the strength of a magnetic field increases in regardless of types of MR fluid or the material. Also the density of particle in MR fluid affects the friction characteristic. The results from this research can be used to improve the performance of mechanical applications using MR fluid.展开更多
Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear.The most common methods for surface texturing are laser and injection molding.The 3D printing...Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear.The most common methods for surface texturing are laser and injection molding.The 3D printing method is also used to build parts,patterns,and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster,more flexible,and less expensive than traditional techniques.To date,there has been no research on textured surfaces produced by 3D printing.Therefore,a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring.In this study,a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing.The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test.The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.展开更多
基金Supported by Basic Science Research Program of National Research Foundation of Korea,Ministry of Education,Science and Technology of the Korean(Grant No.NRF-2015R1D1A1A09060901)Ministry of Science,ICT and Future Planning,Korea,under Convergence Information Technology Research Center(Grant No.IITP-2015-H8601-15-1003) supervised by Institute for Information&Communications Technology PromotionAdvanced Technology Center R&D Program funded by the Ministry of Trade,Industry&Energy of Korea(Grant No.10048876)
文摘Magnetorheological (MR) fluid is a type of a smart material that can control its mechanical properties under a magnetic field. Iron particles in MR fluid form chain structures in the direction of an applied magnetic field, which is known as MR effect, resulting in variation of stiffness, shear modulus, damping and tribological characteristics of MR fluid. As MR effect depends on the density of particles in the fluid or the strength of a magnetic field, the experiments are conducted to evaluate the friction property under reciprocating motion by changing the types of MR fluid and the strength of a magnetic field. The material of aluminum, brass, and steel are chosen for specimen as they are the most common material in mechanical applications. The surfaces of specimen are also observed by optical microscope before and after experiments to compare the surfaces with test conditions. The comparing results show that the friction coefficient increases as the strength of a magnetic field increases in regardless of types of MR fluid or the material. Also the density of particle in MR fluid affects the friction characteristic. The results from this research can be used to improve the performance of mechanical applications using MR fluid.
基金supported by the Basic Science Research Program of the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology of the Korean government(Grant No.NRF-2015R1D1A1A09060901)Ministry of Trade,Industry and Energy via FY 2015 Korea Institute for the Advancement of technology through Construction Machine R&D Expert Cultivation Program
文摘Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear.The most common methods for surface texturing are laser and injection molding.The 3D printing method is also used to build parts,patterns,and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster,more flexible,and less expensive than traditional techniques.To date,there has been no research on textured surfaces produced by 3D printing.Therefore,a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring.In this study,a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing.The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test.The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.